Design and fabrication of tunable microstrip antenna using photodiode as optical switching controlled by Infrared

In this paper, design, fabrication, and characterization new tunable microstrip antenna using photodiode as optical switching has been proposed. The proposed antenna is fabricated in FR-4 substrate 4.8 relative permittivity value. The dimension of the substrate is 47 mm × 75 mm × 1.6 mm. The measurement result indicates that, if photodiode unilluminated by Infrared (OFF state) the proposed antenna works at frequency 4400 MHz with S11 value -16 dB. Meanwhile, if photodiode is illuminated by Infrared (ON state), antenna works at a frequency of 4500 MHz with S11 value - 15 dB. There was a shift of 100 MHz of resonant frequency and -1 dB in S11 value. The proposed antenna are more easily fabricated and the switching methods more simple than other techniques. Also, the cost is relatively cheaper than the other techniques of optical switching.